In portable devices and particularly mobile phones, space utilization is a significant factor in the manufacture of the device. In spite of the space saving, however, the user of the device should be provided with a device which is as functional and reliable as possible. As the user interfaces of mobile phones become more versatile, a multidirectional control switch, such as, for example, a joystick or a navigation key, is becoming more and more significant in improving convenience in use. Consequently, in addition to reliability, convenient functionality and versatile options are required of the control switch, according to the need.
Conventional multidirectional control switches typically comprise a control means which can be tilted in different directions. Thus, by its edge, the tilted control means activates a coupling located in the respective direction, thereby generating information about the direction in which the switch has been controlled. In addition, some multidirectional control switches have the facility to press the switch directly towards the base, whereby it is possible to generate auxiliary control data. Conventionally, multidirectional control switches intended for small electronic devices are 2/3, 4/5 and 8/9-directional, and the information to be obtained from them typically contains the control direction only. For the user, however, it is convenient if the device also operated according to the strength of the pressing; for example, if the user presses the control switch more strongly, the cursor would move faster on the display.
European patent application EP 1 280 173 A2 discloses a digital control switch structure which generates, upon pressing the control switch, information about the length of the pressing in addition to the direction. In said control switch structure, the couplings connected to the circuit board structure are placed in an array of two or more concentric circles in such a way that couplings on different circles are radially aligned in each direction to be indicated. When the control switch is pressed lightly in one direction, the coupling of the first circle is activated. When the control switch is pressed more strongly, the coupling of the second circle is coupled in addition to the coupling of the first circle, indicating information about a long or strong pressing. In said control switch structure, several separate couplings are used, and moreover, it must comprise two or more concentric coupling areas, for which reason the design of the control switch is limited by the structures of the switch and the couplings. Consequently, said structure is primarily suitable for control switches with a maximum of 4/5 directions of movement.